This invention lies in the field of smokeless, noise-suppressed combustion of waste gases.
More particularly, this invention lies in the field of the flaring of waste gases in such a manner as to provide smokeless combustion without excessive noise.
In the art of smokeless flaring of smoked-prone gases, it is common practice to inject steam into the burning zone downstream of the flare to alter the chemistry of burning, in a well known manner, to avoid smoke emission from the burning gases. Because the steam is generally delivered to the combustion zone, at a high pressure, typically 100 psi gauge, the steam injection is productive of excessive noise for several reasons. The most important reason is that with unaltered 100 psig steam (114.7 psia), inflow as from, or through, a single orifice, the steam flow creates shock waves as it emerges to atmospheric pressure at the mouths of the orifices. A second reason for noise generation in excess of specified limits, is that the orifices from which the steam is flowing are generally completely open and exposed, permitting noise radiation to adjacent areas at ground level and also areas remote front the stack.
It is therefore a primary object of this invention to provide a flare system for combustion of waste gases in which high pressure steam is used to promote smokeless combustion, but with a minimum of noise pollution.
It is a further object of this invention to provide a flare for the burning of waste gases in which a protected burning zone free of wind chilling, at the discharge end of the flare, is provided so as to promote stable burning and therefore minimum smoke production.
It is a further object of this invention to provide a type of steam nozzle so that the steam injected into the rising column of burning gas, although at high pressure in the manifold, will not generate noise. It is preferable that steam injection from adjacent nozzles be at varying angles with reference to the horizontal, but not so demanded.
It is a still further object of this invention to provide a type of construction for the stack such that a shroud is provided around the top of the stack which shields the surrounding area from noise generated by the steam jets.